I. Field Of The Invention
This invention relates to an adhesive tape construction for providing a temporary and a permanent seal for an insulation system and, in particular, to a pressure sensitive tape construction which incorporates a releasable cohesive bonding layer for temporary closure during storage and initial installation of the insulation, the cohesive bonding layer being removable to permit permanent seal between adhesive layers and a bond-enhancing surface for final installation of the insulation.
II. Description of the Prior Art
Conventionally, glues, heat or solvent actuatable adhesive films or pressure sensitive tapes have been used to join items such as sections of insulation. Generally, pre-applied pressure sensitive tapes offer the greatest ease of handling and convenience. However, there is a continuous effort to improve the state of the art as to bond strength and temporary closure systems for storage and transport. Tape systems are typically applied in two different manners. A double-faced tape may be applied to one surface and thereafter brought into contact with the other surface to permanently join the surfaces and seal the insulation system. Alternatively, a dual tape system can be employed wherein one strip is applied to one surface and a second strip is applied to the other surface. The bond is affected by bringing the two surfaces together to adhere the tape strips. Prior to permanent sealing, the tacky adhesive surfaces are protected by removable release liners. In a variation of the two tape system, a single intermediate release liner may be used between the adhesive surfaces of each tape in order to join the surfaces during storage. However, because it is often necessary to separate at least one of the adhesive surfaces from the release liner, the adhesive surface can be exposed to dust and debris prior to final bonding resulting in a poor seal. In addition, it is often difficult to obtain exact registration of the adhesive layer with the central release liner if final bonding is not desired resulting in a poor final bond. As a result, the insulation jacket may inadvertently open causing damage to the insulation jacket.
Currently, both supported and unsupported pressure sensitive tapes are used in the insulation industry to join and seal the overlapping ends of the vapor-barrier cover of the pipe insulation jacket. However, these prior known tape constructions do not develop the desired enhanced bond, cannot be applied at sub-freezing temperatures and rely on the coated release liners for resealable connection of the overlapping ends. Using the adhesive layers to temporarily reseal the insulation system deteriorates the adhesive resulting in a poor final bond.